Spinning apparatus for the spinning of hollow filaments



March 19, 1963 w. HEYNEN ETAL SPINNING APPARATUS FOR THE SPINNING OF HOLLOW FILAMENTS Filed Nov. 12, 1958 4 Sheets-Sheet 1 1353321" lllllllliF INVENTORS.

March 19, 1963 w, HEYNEN ETAL 3,081,490

SPINNING APPARATUS FOR THE SPINNING 0F HOLLOW FILAMENTS FiledNov. 12, 1958 4 Sheets-Sheet 2 jya March 19, 1963 w. HEYNEN ET AL SPINNING APPARATUS FOR THE SPINNING OF HOLLOW FILAMENTS Filed NOV. 12, 1958 4 Sheets-Sheet 3 5mg M l mmawm s 7 INVENTORS'.

4 Sheets-Sheet 4 [2 ff a INYIINTORQ. Wan/9 w. HEYNEN ETAL SPINNING APPARATUS FOR THE SPINNING 0F HOLLOW FILAMENTS Filed Nov. 12, 1958 March 19, 1963 United States Patent 3,081,490 SPINNING APPARATUS FOR THE SPINNIN OF HOLLOW FILAMENTS Wilhelm Heynen and Wilhelm Martin, Grebben, Germany, assignors to Vereinigte Glanzstolf-Fabriken AG., Wuppertal-Elberfeld, Germany Filed Nov. 12, 1958, Ser. No. 773,383 Claims priority, application Germany Nov. 16, 1957 4 Claims. (Cl. 18-8) This invention relates to improvements in spinning plates for the spinning of hollow filaments from spinnable polymers.

It is a known practice in the production of hollow filaments to employ spinning nozzles in which, inside the spinning opening proper, a tubular passage is provided. A liquid or gaseous medium is forced through this passage into the interior of the filament as it emerges from the nozzle. In the spinning of viscose filaments, for example, a liquid of the same or similar composition to the spinning bath is conducted through the inner passage so that directly on the emergence of the viscose from the nozzle a coagulation or decomposition of the viscose spinning solution takes place, both from the outside and also on the inside of the hollow filament. In the production of synthetic threads by the melt-spinning process, an inert gas is blown through the tubular passagepreventing collapse of the molten filament emerging from the nozzle.

The manufacture of nozzles useful for the production of hollow filaments, especially filaments produced by the melt-spinning process, is extraordinarily difiicult because the spinning openings have 'to be bored with extreme precision and the tolerances are very small in centering of the passage through which the gaseous agent is conducted. A further difiiculty arises from the necessity of connecting the hollow passage with a gas feed line, on the one hand, and the feed passage for the molten' spin- .ning mass with a spinning mass feed line on the other hand plus creating passages inside the nozzle itself to provide uniform distribution of the molten spinning mass.

The majority of the known nozzles for the production of hollow threads consist of at least two plates, which are spaced apart by a gasket. The hollow space between these plates forms the feed space for the spinning mass, while the supply of liquid or gaseous agents is accomplished in these nozzles from above. In the upper plate are solidly anchored hollow tubes, which pass through the feed space for the spinning mass and through spinning openings in the lower plate. In order to achieve a centering of the hollow tubes in the lower plate forming the nozzle base, these hollow passages may be equipped with a thickened shaft, or they may be solidly connected with the nozzle base plate at several points. Nozzle designs in which there is no solid connection between the nozzle base plate and hollow tubes are, both from a production and also a cleaning viewpoint, more advantageous than nozzles in which a solid connection is used between hollow tubes and nozzle base plate. In the production of such nozzles, the two plates can be produced in such a manner that capillaries are installed in prefinished openings of the upper plate. At the lower end, these capillaries are provided with thickened portions, which are used to center a capillary tube in each spinning bore. In the lower plate, the spinning openings are drilled, and the two plates are assembled so that a feed space for the molten spinning mass is formed between the inner wall of the spinning bore and the outer surface of the capillary tube. With the requisite small diameters of the nozzle bores, on the one hand, and of the capillaries forming the hollow passages, on the other hand, it is extremely difficult to assemble the two plates without accidental deformation of the capillary tubes.

In those nozzles in which the hollow passages are connected solidly with the upper plate and also with the lower plate, the manufacture is accomplished in such a manner that the entire nozzle is produced from one piece. For example, laminated bodies of various chemical substances are produced. Then some chemicals are removed out by chemical or mechanical means, so that the parts forming the finished nozzles remain. It is obvious that such a manufacturing process is extremely complicated and time-consuming, and it is only rarely that it can be carried out with the necessary precision.

The object of the present invention is to provide a spinning nozzle which can be manufactured much more simply and with greater precision than that of hollow filament nozzles described above. The spinning nozzle is composed of two separate plates, which are joined by means of screws or equivalents thereof without the conventional hollow space between them. One of these plates has feed passages for gaseous or fluid media and also for the spinning mass. The latter are connected with a cylindrical feed manifold for the spinning mass, which is formed by a cylindrical recess in the plate. The other plate contains the spinning openings, into each of which extends a centrally-disposed, hollow tubular member which terminates a capillary tube. This hollow tubular member is likewise produced separately. It is not solidly connected with the first-mentioned plate, but is drawn tightly in the bore provided for it in the plate by means of a screw. A ring-shaped shoulder on the hollow tubular member of a diameter larger than the bore in the plate provides for the secure, precise mounting of the tubular member or members on the plate. In order to preclude the danger of damage to the capillaries during the joining of the two plates-after the hollow passage is connected with the upper platethe upper plate is equipped with two guide prongs, which are longer than the part of the hollow passage protruding into the spinning opening, including the capillaries. In the lower plate there are corresponding bores provided for the guide prongs. In the assembled nozzle, the guide prongs project somewhat over the nozzle base. Between the contact surface on the hollow passage and under the head of the screw and the nozzle plate, packings of various thickness can be inserted. It is hereby possible to vary the position of the capillary in the spinning opening with respect to the surface of the nozzle base. For example, the capillary may project somewhat from the nozzle base or be retracted in accordance with the thickness of the packing.

Specific embodiments of the invention are illustrated in the drawings wherein:

FIG. 1 is aside elevation in diametric cross-section, taken along section 11 of FIG. 2, of one form of the invention; 7

FIG. 2 is a top plan view of the embodiment of FIG. 1;

FIG. 3 is a partial cross-section view of the embodiment of FIG. 1 illustrating the guide pin structure used in assembling the nozzle plates of the instant invention;

FIG. 4 is a cross-sectional view taken along section 4-4 of FIG. 2;

FIG. is an enlarged sectional view of a tubular member used in the embodiment of FIG. 1;

FIG. 6 is a cross-sectional view of a modified form of the tubular member shown in FIG. 5;

FIG. 7 is a cross-sectional view taken along section 77 of FIG. 6;

FIG. 8 is a diametric cross-sectional view of another embodiment of the invention wherein the spinning plate has a plurality of spinning orifices for the spinning of hollow filaments;

FIG. 9 is a top plan view of the embodiment of FIG. 8;

FIG. is a cross-sectional view taken along section 1010 of FIG. 9; and

FIG. 11 is a partial, broken view of a spinning head showing in cross-section the mounting of a spinning nozzle containing the spinning plates of FIGS. l-4.

With regard to the embodiment of FIGS. 1 -4, the spinning plate therein illustrated is made up of a discshaped base plate 1 and a similar disc-shaped second plate 2 mounted in face to face relationship with said base plate. The plate 2 has a radial passage 3 for conducting a fluid, either gas or liquid, to a central bore 4 provided in the plate 2. The plate 2 also has four passages 5, which are parallel with and disposed about the central bore 4. The bore 4 and passages 5 communicate the outer face of the plate 2 with a cylindrically-shaped recess disposed centrally in the disc-shaped plate 2 at the face of the plate 2 opposite the plate 1. The cylindrical recess 6 serves as a manifold for communicating the passages 5 with a central spinning orifice extending through the plate 1.

The spinning orifice 7 is composed of a relatively large cylindrical segment 7a and may, if desired, have a counter-sunk edge 7b at the face of the plate 1 opposite the plate 2. The opposite end of the cylindrical portion 7a is tapered at 70 to a spinning opening 7d of the desired size.

The plates 1 and 2 are held in assembled relationship by means of screws 8, which threadably engage internally threaded holes 9 in the plate 2. The screw heads 10 of screws 8 are preferably positioned within recesses 11 provided in the exterior face of the plate 1. To fa cilitate proper alignment of the plates 1 and 2 during the assembly thereof, the plate 2 is provided with two or more guide pins 12, which will extend through correspondingly positioned guide holes 13 in plate 1. These guide pins facilitate proper alignment of the plates during the assembly operation and prevent accidental damage to the delicate capillary tubes hereinafter described. When the plates 1 and 2 are assembled an O-ring packing 14 is inserted between the plates to form a fluid-tight seal therebetween. A preferred packing material is an aluminum gasket which, before compression, has a thickness of about 0.1 millimeter. When the screws 10 are tightened, the plates 1 and 2 are virtually in contact with one another.

The assembly heretofore described constitutes that portion of the apparatus for conducting a spinnable polymer through the plates and out of the spinning opening 7d. The portion of the apparatus for providing a fluid inside the filament as it is being spun is composed of a tubular insert designated generally by the numeral 15. This insert is shown in detail in FIG. 5. The tubular insert 15 has an axial passage 16 which communicates with a centrally-disposed capillary tube 17 which protrudes from the end of the tubular insert 15. A radial aperture extending through the wall of the tubular insert 15 also communicates with the axial passage 16 for the purpose of supplying a fluid, either a gas or liquid, to the axial passage 16 and thence to the capillary tube 17. The end of the radial aperture 18 opposite the axial aperture 16 opens in an annular groove or recess 19, which is provided for a purpose later described.

The tubular insert 15 has intermediate the ends thereof an annular ring 20 with an upper contact shoulder 21.

' The upper portion 23 of the tubular insert 15 has an internally-threaded bore 22 for threadedly engaging the threaded shank 24 of a screw.

The embodiment of the tubular insert of FIG. 6 is similar to that shown in FIG. 5 and, for the sake of convenience, like numerals have been used to designate like parts. The primary difference between the embodiment of FIGS. 5 and 6 is that the latter is provided with guide vanes 25 which, in end view, are in the shape of a cross. These guide vanes are adapted to contact the walls of the central bore 7 to properly guide the tubular insert with its fragile capillary tube 17 through the bore and to position the capillary tube 17 centrally in the spinning opening 7d.

The tubular inserts 15 are, thus, separate component parts which are removably mounted in the plates 1 and 2. The mounting of the tubular inserts 15 is done by mounting the inserts in the plate 2 before the latter is assembled with plate 1. This mounting is carried out by removing the screw 24 from the insert 15 and fitting the upper portion 23 into the central bore 4 of the plate 2 from the side of the plate 2 containing the recess 6. To provide a fluid-tight fit between the tapered edges 26 of the central bore 4 and the shoulder 21 of the tubular insert 15, there may be provided a packing member 27. After threading the screw 24 into the bore 22 of the tubular insert 15 and also providing a packing 28 between the upper tapered portion of the bore 4 and the bottom side of the screw 24, the upper plate 2 is then ready for assembly with the lower plate 1 in the manner previously described. The packings 27 and 28 thus form a fluidtight chamber within the central bore 4. Thus, the fluid, either gas or liquid, supplied to the passage 3 flows into the fluid-tight chamber in the central bore 4 and thereafter through passages 18 and 16 into the capillary tube 17. The annular groove or recess 19 provides a free passage for the fluid, and it is, hence, unnecessary to be concerned with proper alignment between the passage 3 and the aperture 18.

In a typical spinning process, the spinnable polymer flows from the upper face of the plate 2 through vertical passages 5 into the recess 6, from whence it flows into the spinning orifice 7 and thence out of the spinning opening 7d in the form of a filament. In a melt-spinning process, the filament emerging from the opening 7d is solidified in air or other gaseous medium. In the wetspinning process, the filament emerges from the opening 7d into a coagulation or precipitation bath, which causes the spinnnig solution to coagulate or solidify. Simultaneous with the extrusion of the spinnable polymer, a fluid is supplied through the capillary tube 17 into the center of the filament as it is being extruded. In the meltspinning processes this fluid is normally a gas and in wetspinning processes the fluid usually will be a liquid of similar or identical composition to the spinning bath.

The primary advantage of the assembly previously described -over known assemblies for performing the same function is the ease in manufacture of the individual parts, the ease of assembly thereof, and the precision attainable between the pants thereof-the most important being the relationship between the capillary tube 17 and the opening 7d. Furthermore, inasmuch as the tubular insert 15 can be easily removed from the plate 2, the cleaning of the apparatus and the reassembly thereof is considerably improved.

The embodiment of the invention illustrated in FIGS. 8-10 is similar to that of FIGS. 1-4-the primary difference being the provision in the spinning plate assembly of FIGS. 8-10 of a plurality of spinning orifices for simultaneously spinning a plurality of hollow filaments. Where applicable, like numerals have been used to designate like parts and reference is made to previous description for explanation of these reference numerals.

In this embodiment of the invention the plate 2 has a tapered central bore 29. there is cut a ring bore 30.

the bore 29 are isolated from each other by inserting a tapered sleeve 31, made of metal, such as aluminum or of other suitable gasket material. The plate 2 also has six vertical bores 32 disposed in circular fashion about the ce'ntal bore 29 with the edges of the bores 32 intercepting the ring bore 30. The plate 2 has a radial bore 33 which communicates the outer edge of the plate 2 with the ring bore 30. Like the embodiment of FIGS. 1-4, the plate 2 has on the face opposite plate 1 a central recess 34 of a diameter sufficiently large to provide communication with each of the bores 35 in the plate 1 when the two plates are assembled. The remaining details of the embodiment illustrated in FIGS. 8-10 will be apparent from the description with respect to FIGS. 14.

The spinning mass is fed through the sleeve 31 into the recess 34, which serves as a manifold for distributing the spinning mass to each of the spinning bores 35 in the plate 1. The fluid discharged into the center of the spinning mass through capillary tubes 17 is supplied through passage 33 into the ring bore 30 and thence into each of the bores 32 in the plate 2. The fluid medium then passes through the tubular inserts 15 and out of the capillary tubes 17 in the manner previously described with respect to FIGS. 14.

FIG. 11 illustrates the mounting of the spinning plates in a spinning nozzle, which nozzle, in turn, is mounted in a spinning head. The spinning head 52 (only a segment being shown) has a cylindrical bore 53 into which is press fitted a spinning nozzle 45. Inside the spinning nozzle 45 there is provided a holder 36 for holding the plates 1 and 2 in the spinning nozzle. The holder 36 has a central bore comprising a cylindrical portion 36a, a tapered portion 36b and a cylindrical portion 36c. At the end of the cylindrical portion 36c there is an inwardlyturned flange 37 which bears against the plate 1. Abutting against the plate 2 is an aluminum ring 38, which holds the filter member 39the latter functioning to screen out any particles which would block the small passages in the spinning apparatus. The filter 39 is spaced from the plate 2 to provide a feed space 40. Also within the holder 36 is a washer-like plate 41 of generally cylindrical shape with a tapered portion corresponding to the taper at 36b. The plate 41 has a spinning mass feed passage 42 extending therethrough. O-ring packings 43 and 44 are provided to seal the spinning apparatus against flow of the spinning mass to undesired areas.

The holder 36 and its contained parts are held within the recess of the spinning nozzle 45 by means of a cylindrical sleeve 54, which has an inwardly-turned flange 55. The sleeve 54 is externally-threaded for threaded engagement with internal threads provided on the cylindrical walls of the recess in the spinning nozzle 45. The rear face of the nozzle 45 has a passage 47 through which the spinning mass supplied under pressure to the spinning head passes for subsequent passage through the parts of the spinning nozzle from which it eventually emerges as a filament.

After the holder 36 and its component parts are assembled in the nozzle 45 in the manner illustrated, the parts are tightly engaged and the packings 43 and 44 compressed by turning down threaded bolts 48 evenly spaced about the inwardly-turned flange 55. These bolts bear against a shoulder on the holder 36 and, thus, the parts may be assembled in fluid-tight relationship.

The holder 36 has in the cylindrical portion 36c an annular groove 49. The groove 49 is positioned to correspond with the position of the passage 3 in the plate 2. Thus, a fluid supplied -to the annular groove 49 through the vertical passage 50 in the holder 36 and the tube 51 inserted therein, will be supplied through the passage 3 w to the capillary tube 17 in the manner previously described.

It will be seen from the foregoing description that the nozzles of the instant invention are made of parts which can be machined relatively easily. The hollow inserts, because they are produced separately, can be produced with the necessary precision. The invention herein described is also advantageous inasmuch as the spinning nozzles can be taken apart, cleaned and reassembled with out difliculty and, if need be, the tubular inserts can be changed without replacing other parts of the apparatus.

The invention is hereby claimed as follows:

1. A spinning nozzle for spinning hollow filaments comprising a first plate and a second plate mounted in face to face relationship with each other, a recess in the face of one of said plates contiguous to the other of said plates, a cylindrical passage in said second plate communicating with said recess and terminating in a spinning orifice at the outer surface of said second plate, said first plate having a bore extending from the outer face thereof to said recess, said bore being aligned with said passage in said second plate, a tubular insert having a ring-shaped portion intermediate the ends thereof extending through said bore and into said passage, the ringshaped portion forming a shoulder in contact with the face of the recess about said bore, said tubular insert having a radial aperture through the wall thereof and ending in a capillary tube centrally disposed in said spinning orifice, a passage for supplying a spinning mass through said first plate to said recess, and passage means in said first plate for supplying a fluid to said tubular insert through said radial aperture in the latter.

2. A spinning nozzle comprising a first plate and a second plate mounted in face to face relationship, a recess in the face of one of said plates contiguous to the other of said plates, said first plate having a bore communicating the outer surface of said plate and said recess, the side wall of said bore having a continuous groove therein, a sleeve tightly fitted in said bore for dividing the groove and the bore into separate fluid conducting passages, said first plate having a radial passage communicating said groove and a side wall of said first plate, said second plate having a plurality of spinning passages terminating in spinning orifices at the outer surface of the second plate, said passages communicating with said recess, a plurality of bores extending through said first plate from the outer surface thereof to said recess and also intercepting said groove, each of said passages being aligned with one of said passages in said second plate, tubular inserts being removably mounted in each of said lastmentioned bores in said first plate, each of said inserts having a passage communicating the hollow interior there of with said groove, and each of said tubular inserts terminating in a capillary tube positioned in thecorresponding spinning orifice.

3. A spinning nozzle as claimed in claim 2 wherein said passage in each of said inserts is a radial passage through the tubular Wall of said tubular inserts.

4. A spinning nozzle for the spinning of hollow filaments comprising a first plate and a second plate mounted in face to face relationship with each other, a recess in the face of one of said plates contiguous to the other of said plates, a cylindrical passage extending through said second plate, said passage communicating at one end with said recess and terminating at the other end in a spinning orifice of a diameter less than the diameter of said passage, an insert removably mounted in said first plate, said insert having a tubular section of smaller diameter than the diameter of said passage and substantially concentrically located in said passage, said tubular section terminating in an end wall with an aperture therethrough, said aperture having fixedly mounted therein a thin-walled, cylindrical, capillary tube of a diameter less than the diameter of said spinning orifice and extending into said spinning orifice in substantially concentric relation therewith, said first plate containing a passage for supplying a spinning mass through said first plate to said recess, and communicating passage means 'in said first plate and said tubular insert for supplying a fluid to said capillary tube of said tubular insert.

References Cited in the file of this patent UNITED STATES PATENTS Cowen June 6, 1939 Kunz Mar. 26, 1940 Holzrnann Oct. 17, 1944 Raiche Oct. 5, 1954 Allan et a1. Mar. 8, 1955 10 3 Terracini ct a1 Oct. 8, 1957 Breen Nov. 25, 1958 Breen Apr. 5, 1960 Dietzsch et a1. Apr. 12, 1960 Breen Sept. 12, 1961 Brcen Oct. 10, 1961 FOREIGN PATENTS France Nov. 13, 1944 France Sept. 30, 1957 

1. A SPINNING NOZZLE FOR SPINNING HOLLOW FILAMENTS COMPRISING A FIRST PLATE AND A SECOND PLATE MOUNTED IN FACE TO FACE RELATIONSHIP WITH EACH OTHER, A RECESS IN THE FACE OF ONE OF SAID PLATE CONTIGUOUS TO THE OTHER OF SAID PLATES, A CYLINDRICAL PASSAGE IN SAID SECOND PLATE CONMUNICATING WITH SAID RECESS AND TERMINATING IN A SPINNING ORIFICE AT THE OUTER SURFACE OF SAID SECOND PLATE, SAID FIRST PLATE HAVING A BORE EXTENDING FROM THE OUTER FACE THEREOF TO SAID RECESS, SAID BORE BEING ALIGNED WITH SAID PASSAGE IN SAID SECOND PLATE, A TUBULAR INSERT HAVING A RING-SHAPED PORTION INTERMEDIATE THE ENDS THEREOF EXTENDING THROUGH SAID BORE AND INTO SAID PASSAGE, THE RINGSHAPED OF THE RECESS ABOUT SAID BORE, SAID TUBULAR INSERT FACE OF THE RECESS ABOUT SAID BORE, SAID TUBULAR INSERT HAVING A RADIAL APERTURE THROUGH THE WALL THEREOF AND 